Novel tertiary amine compounds having an ester structure and processes for preparing same

ABSTRACT

The present invention provides novel and useful ester group-containing tertiary amine compounds which, when used as additives in chemical amplification photolithography, can yield photoresists having a high resolution and an excellent focus margin. Specifically, the present invention provides ester group-containing tertiary amine compounds represented by the following general formula (1). As processes for preparing these compounds, the present invention also provides a process comprising the step of subjecting a primary or secondary amine compound represented by the following general formula (5) to Michael addition to an acrylic ester compound represented by the following general formula (6); a process comprising the steps of subjecting monoethanolamine or diethanolamine represented by the following general formula (7) to Michael addition to an acrylic ester compound represented by the following general formula (6) so as to form an ester group-containing amine compound represented by the following general formula (8), and introducing the R 1  group thereinto; and a process comprising the step of effecting the ester exchange reaction of an ester group-containing tertiary amine represented by the following general formula (9), with R 2 OH.

BACKGROUND OF THE INVENTION

[0001] 1. Filed of the Invention

[0002] This invention relates to novel ester group-containing tertiaryamine compounds which are useful as additives for novel chemicalamplification resists suitable for fine processing techniques.

[0003] 2. Description of the Related Art

[0004] While increasingly finer pattern rules are required as the degreeof integration and speed of LSIs become higher, far ultravioletlithography is regarded as a promising fine processing technique of thenext generation. Far ultraviolet lithography is capable of processingdown to a size of 0.2 μm or less, and when a resist material having lowlight absorption is used, permits the formation of patterns havingsidewalls substantially perpendicular to the substrate. Moreover, atechnique using a high luminance KrF excimer laser as the light sourceof far ultraviolet radiation is attracting attention in recent years. Inorder to employ this technique as a mass production technique, a resistmaterial having low light absorption and high sensitivity is desired.

[0005] From this point of view, chemically amplified positive resistmaterials using an acid as the catalyst have recently been developed (asdisclosed, for example, in Japanese Patent Publication No. 2-27660/'90and Japanese Patent Provisional Publication No. 63-27829/'88). Theseresist materials have excellent characteristics such as highsensitivity, high resolution and high dry etching resistance, and arehence particular promising for use in far ultraviolet lithography.

[0006] One disadvantage of chemically amplified resists is that, if theresist is allowed to stand for a long time between light exposure andPEB (Post Exposure Bake), the formed line patters have a T-top shape,i.e. the patterns have a thickened upper part (this problem is referredto as PED (Post Exposure Delay)). Another disadvantage is the so-calledfooting phenomenon in which the lower part of the patterns is thickenedin the neighborhood of the substrate especially when the substratecomprises a basic material such as silicon nitride or titanium nitride.It is considered that the T-top phenomenon is due to a reduction in thesolubility of the resist film at the surface, and the footing phenomenonon the substrate surface is due to a reduction in the solubility of theresist film in the neighborhood of the substrate. Moreover, a problemarises in that a dark reaction eliminating an acid-labile group proceedsduring a period of time extending from light exposure to PEB, resultingin a reduction in line dimensions.

[0007] These problems present serious drawbacks when chemicallyamplified resists are put to practical use. Owing to these drawbacks,conventional chemically amplified positive resist materials have beenunsatisfactory in that dimensional control is difficult not only inlithographic steps but also in substrate processing by dry etching (see,for example, W. Hinsberg et al., J. Photopolym. Sci. Technol., 6(4),535-546(1993); and T. Kumada et al., J. Photopolym. Sci. Technol., 6(4),571-574(1993)).

[0008] In chemically amplified positive resist materials, the problemsof PED and footing on the substrate surface are considered to be closelyrelated to basic compounds present in air or on the substrate surface.The acid formed in the surface of the resist film by exposure to lightis inactivated by reaction with basic compounds in air. As the standingtime till PEB is prolonged, the amount of acid inactivated increasesand, therefore, the acid-labile group becomes hard to decompose.Consequently, a hardly soluble layer is formed at the film surface andthe patterns assume a T-top shape.

[0009] It is well known that the addition of a basic compound suppressesthe influence of basic compounds in air and is hence effective againstPED (U.S. Pat. No. 5,609,989, WO 98/37458, Japanese Patent ProvisionalPublication No. 63-149640/'88, Japanese Patent Provisional PublicationNo. 5-113666/93, Japanese Patent Provisional Publication No.5-232706/'93 (U.S. Pat. No. 5,580,695) and Japanese Patent ProvisionalPublication No. 5-249662/'93 (U.S. Pat. No. 5,968,712 and 20010038964)).

[0010] Well-known basic compounds are nitrogen-containing compounds suchas amine compounds and amide compounds having a boiling point of 150° C.or above. Specific examples thereof include polyvinylpyridine, aniline,N-methylaniline, N,N-dimethylaniline, o-toluidine, m-toluidine,p-toluidine, 2,4-lutidine, quinoline, isoquinoline, formamide,N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide,N,N-dimethylacetamide, 2-pyrrolidone, N-methylpyrrolidone, imidazole,α-picoline, β-picoline, γ-picoline, o-aminobenzoic acid, m-aminobenzoicacid, p-aminobenzoic acid, 1,2-phenylenediamine, 1,3-phenylenediamine,1,4-phenylenediamine, 2-quinolinecarboxylic acid, 2-amino-4-nitrophenol,and triazine compounds such as2-(p-chlorophenyl)-4,6-trichloromethyl-s-triazine. Among them,pyrrolidone, N-methylpyrrolidone, o-aminobenzoic acid, m-aminobenzoicacid, p-aminobenzoic acid and 1,2-phenylenediamine are especiallypreferred.

[0011] These nitrogen-containing compounds are weak bases, and canmitigate the T-top problem. However, when a highly reactive acid-labilegroup (e.g., an acetal group such as 1-ethoxyethyl) is used, it isimpossible to control the reaction, i.e., the diffusion of the acid. Theaddition of a weak base has been disadvantageous especially in that thedark reaction during PED proceeds in unexposed regions and causes areduction in line size (slimming) and a film loss at the line surface inthe case of an acetal-derived acid-labile leaving group. In order tosolve these problems, it has been effective to add a strong base.However, it may not be definitely said that a compound having a higherbasicity is more effective. In fact, the addition of so-calledsuperstrong bases such as DBU (1,8-diazabicyclo[5.4.0]-7-undecene), DBN(1,5-diazabicyclo[4.3.0]-5-nonene), proton sponge, and quaternary amines(e.g., tetramethylammonium hydroxide) has failed to produce a sufficienteffect.

[0012] The effects produced by the addition of a basic compound to aresist composition include not only an improvement in environmentalstability, but also an enhancement in resolution. The addition of a basereduces sensitivity, but enhances contrast in acid release. In exposedregions where the number of moles of the acid released is smaller thanthe number of moles of the base added, the acid is inactivated byneutralization with the base, and is unable to cause a catalyticreaction. However, as soon as the neutralization point is exceeded, anacid is suddenly released to cause a catalytic reaction.

[0013] The phenomenon of sudden acid release induced by the addition ofa base in the vicinity of the neutralization point was called a protonjump by Hatakeyama et al. (SPIE Symp. Proc., 3333, 62(1998)). Moreover,Hatakeyama et al. carried out a close investigation on the mechanism ofa proton jump and proposed a competitive reaction theory that theneutralization reaction between the acid formed by exposure to light andthe base takes place at the same time as the reaction catalyzed by theacid occurs (J. Photopolymer. Sci. Technol., Vol. 13(4), p. 519(2000)).They solved kinetically the neutralization reaction between the acidformed photochemically and the base added, and showed that a base havinga greater reaction rate constant can give higher contrast.

SUMMARY OF THE INVENTION

[0014] Our experiments performed by the addition of various bases haverevealed that there is no close relationship between the reaction rateconstant and pKa of acids. For example, triethanolamine having a lowerbasicity has been found to have a greater reaction rate constant thanso-called superstrong bases such as DBU(1,8-diazabicyclo[5.4.0]-7-undecene), DBN(1,5-diazabicyclo[4.3.0]-5-nonene), proton sponge, quaternary amines(e.g., tetramethylammonium hydroxide), sodium hydroxide and potassiumhydroxide. Moreover, tris[2-(methoxymethoxy)-ethyl]amine andtris[2-{(2-methoxyethoxy)methoxy}ethyl]amine have been found to have agreater reaction rate constant and give higher contrast thantriethanolamine. In this connection, these bases are estimated to have apKa of around 7, and are much weaker bases than DBU, DBN, quaternaryammonium hydroxide and proton sponge that have a pKa of the order of 13.

[0015] From these facts, it has been made clear that the bases added toresists need not be superstrong bases, but amines having a polarfunctional group such as a hydroxyl or ether group are effective.However, even these bases are not satisfactorily effective in preventinga film loss, enhancing the contrast, and extending the focus margin.Accordingly, there is a need for the development of a more suitablebase.

[0016] The present invention has been made in view of theabove-described circumstances, and an object thereof is to provide noveland useful ester group-containing tertiary amine compounds which, whenused as additives in chemical amplification photolithography, can yieldphotoresists having a high resolution and an excellent focus margin, aswell as processes for preparing these compounds.

[0017] The present inventors carried out intensive investigations with aview to accomplishing the above object. As a result, it has been foundthat tertiary amines having a specific structure containing an estergroup as represented by the following general formula (1) can beobtained in high yields and with simplicity by employing any of theprocesses which will be described later, and that these estergroup-containing tertiary amine compounds are highly effective inpreventing a loss of the resist film, enhancing the resolution, andextending the focus margin.

[0018] That is, the present invention provides ester group-containingtertiary amine compounds represented by the following general formula(1). Moreover, as processes for the preparation of estergroup-containing tertiary amine compounds represented by the followinggeneral formula (1), the present invention also provides a processcomprising the step of subjecting a primary or secondary amine compoundrepresented by the following general formula (5) to Michael addition toan acrylic ester compound represented by the following general formula(6); a process comprising the steps of subjecting monoethanolamine ordiethanolamine represented by the following general formula (7) toMichael addition to an acrylic ester compound represented by thefollowing general formula (6) so as to form an ester group-containingamine compound represented by the following general formula (8), andintroducing the following R¹ group thereinto; and a process comprisingthe step of effecting the ester exchange reaction of an estergroup-containing tertiary amine represented by the following generalformula (9), with R²OH.

[0019] wherein n is 1 or 2; R¹ and R² each independently represent astraight-chain, branched or cyclic alkyl group of 1 to 20 carbon atomswhich may contain an ether, carbonyl or carbonyloxy group; R⁴ representsan alkyl group of 1 to 4 carbon atoms; and X represents a leaving groupsuch as halogen, alkylsulfonyloxy, acyloxy, hydroxyl or aryloxy.

[0020] Resist materials prepared by adding ester group-containingtertiary amine compounds in accordance with the present invention have ahigh resolution and an excellent focus margin, and are useful for fineprocessing with electron rays or far ultraviolet radiation. Inparticular, since their addition can produce an excellent effect in KrFresists, ArF resists, F₂ resists and EB resists, these resists aresuitable for use as fine pattern forming materials for the manufactureof VLSIs.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The present invention will be more specifically describedhereinbelow.

[0022] In the general formula (1) of the present invention, R¹preferably has 1 to 10 carbon atoms and R² preferably has 2 to 10 carbonatoms. Such ester group-containing tertiary amine compounds can berepresented by the following general formula (2).

(R^(1′)OCH₂CH₂)_(n)N(CH₂CH₂CO₂R^(2′))_(3-n)  (2)

[0023] wherein n is 1 or 2; R^(1′) each independently represents analkyl group of 1 to 10 carbon atoms which may contain an ether, carbonylor carbonyloxy group; and R^(2′) represents a straight-chain, branchedor cyclic alkyl group of 2 to 10 carbon atoms which may contain anether, carbonyl or carbonyloxy group.

[0024] Moreover, in the general formula (1) of the present invention, R¹is preferably a formyl or acetyl group and R² preferably has 2 to 10carbon atoms. Such ester group-containing tertiary amine compounds canbe represented by the following general formula (3).

(R¹OCH₂CH₂)_(n)N(CH₂CH₂CO₂R^(2′))_(3-n)  (3)

[0025] wherein n is 1 or 2; R^(2′) represents a straight-chain, branchedor cyclic alkyl group of 2 to 10 carbon atoms which may contain anether, carbonyl or carbonyloxy group; and R¹ represents a formyl oracetyl group.

[0026] Furthermore, in the general formula (1) of the present invention,R¹ is preferably a methyl group and R² preferably has 2 to 10 carbonatoms. Such ester group-containing tertiary amine compounds can berepresented by the following general formula (4).

(CH₃OCH₂CH₂)_(n)N(CH₂CH₂CO₂R^(2′))_(3-n)  (4)

[0027] wherein n is 1 or 2; and R^(2′) represents a straight-chain,branched or cyclic alkyl group of 2 to 10 carbon atoms which may containan ether, carbonyl or carbonyloxy group.

[0028] In the ester group-containing tertiary amine compounds of thegeneral formulas (1) to (4) in accordance with the present invention,examples of R¹ include, but are not limited to, methyl, ethyl, propyl,isopropyl, butyl, s-butyl, isobutyl, t-butyl, pentyl, cyclopentyl,hexyl, cyclohexyl, decyl, methoxymethyl, 2-methoxyethyl, 1-ethoxyethyl,2-ethoxyethyl, (2-methoxyethoxy)methyl, 2-tetrahydrofuranyl,2-tetrahydropyranyl, tetrahydrofurfuryl, formyl, acetyl, propionyl,butyryl, isobutyryl, pivaloyl, valeryl, methoxyacetyl, ethoxyacetyl,acetoxyacetyl, 2-formyloxyethyl, 2-acetoxyethyl, 2-oxopropyl,2-oxobutyl, 2-oxocyclopentyl, 2-oxo-3-tetrahydrofuranyl,2-oxo-3-tetrahydropyranyl, methoxycarbonyl, ethoxycarbonyl andt-butoxycarbonyl.

[0029] In the ester group-containing tertiary amine compounds of thegeneral formulas (1) to (4) in accordance with the present invention,examples of R² include, but are not limited to, methyl, ethyl, propyl,isopropyl, butyl, s-butyl, isobutyl, pentyl, isopentyl, cyclopentyl,hexyl, cyclohexyl, octyl, 2-ethylhexyl, decyl, stearyl, 2-methoxyethyl,2-ethoxyethyl, 2-propoxyethyl, 2-isopropoxyethyl, 2-butoxyethyl,2-cyclohexyloxyethyl, 2-methoxy-1-methylethyl, 3-ethoxypropyl,3-butoxypropyl, 2-(2-methoxyethoxy)ethyl, 2-(2-ethoxyethoxy)ethyl,2-[2-(2-methoxyethoxy)ethoxy]ethyl, 2-[2-(2-ethoxyethoxy)ethoxy]ethyl,3-tetrahydrofuranyl, tetrahydrofurfuryl, 3-tetrahydrofuranylmethyl,2-tetrahydropyranylmethyl, tetrahydro-4H-pyran-4-yl, 1,3-dioxan-5-yl,1,3-dioxolan-4-ylmethyl, 2,2-dimethyl-1,3-dioxolan-4-ylmethyl,2-formyloxyethyl, 2-acetoxyethyl, 2-propionyloxyethyl,2-(methoxyacetoxy)ethyl, 2-(acetoxyacetoxy)ethyl,2-(methoxycarbonyloxy)ethyl, 2-(ethoxycarbonyloxy)ethyl,2-(butoxycarbonyloxy)ethyl, 2-(isobutoxycarbonyloxy)ethyl,2-(t-butoxycarbonyloxy)ethyl, 2-(pentyloxycarbonyloxy)ethyl,2-(hexyloxycarbonyloxy)ethyl, 2-(heptyloxycarbonyloxy)ethyl,2-(octyloxycarbonyloxy)ethyl, 2-(2-nonyloxycarbonyloxy)ethyl,2-(decyloxycarbonyloxy)ethyl, 2-(2-methoxyethoxycarbonyloxy)ethyl,2-(methoxycarbonylmethoxy)ethyl, 2-(ethoxycarbonylmethoxy)ethyl,4-formyloxybutyl, 4-acetoxybutyl, 4-propionyloxybutyl,4-(methoxyacetoxy)butyl, 4-(acetoxyacetoxy)butyl,4-(methoxycarbonyloxy)butyl, 2-(ethoxycarbonyloxy)butyl,4-(butoxycarbonyloxy)butyl, 4-(isobutoxycarbonyloxy)butyl,4-(t-butoxycarbonyloxy)butyl, 4-(pentyloxycarbonyloxy)butyl,4-(hexyloxycarbonyloxy)butyl, 4-(heptyloxycarbonyloxy)butyl,4-(octyloxycarbonyloxy)butyl, 4-(2-nonyloxycarbonyloxy)butyl,4-(decyloxycarbonyloxy)butyl, 4-(2-methoxyethoxycarbonyloxy)butyl,formyloxypropyl, acetoxypropyl, 2-oxo-1-propyl, 2-oxo-1-butyl,2-oxocyclopentyl, 2-oxocyclohexyl, 2-oxo-3-tetrahydrofuranyl and2-oxo-3-tetrahydropyranyl.

[0030] Specific examples of the ester group-containing tertiary aminecompounds of the present invention include, but are not limited to, thefollowing compounds.

[0031] According to the present invention, it is believed that, in theseester group-containing tertiary amine compounds, an ester group andother oxygen-containing functional group having a high affinity foracids can be located at an appropriate position in the vicinity of theamine nitrogen atom so as to realize a high reaction rate with acids,and photoresists having these tertiary amine compounds added thereto canhence achieve a high resolution and a wide focus margin. Moreover, it isalso believed that their basicity, reaction rate with acids, anddiffusion rate in the resist can be properly controlled by selecting themost suitable combination of R¹ and R² in the general formula (1),making it possible to provide amine additives suitable for a widevariety of resist polymers and acid generators.

[0032] The ester group-containing tertiary amine compounds of thepresent invention, which are represented by the general formula (1), maybe prepared, for example, by selecting the most suitable process fromamong the following processes according to the structure of the desiredcompound. However, it is to be understood that the present invention isnot limited thereto. Now, these preparation processes are specificallydescribed below.

[0033] As a first process, they may be synthesized in one step from aprimary or secondary amine compound and an acrylic ester compound byutilizing the Michael addition reaction of an amine.

[0034] wherein n is 1 or 2; and R¹ and R² each independently representsa straight-chain, branched or cyclic alkyl group of 1 to 20 carbon atomswhich may contain an ether, carbonyl or carbonyloxy group.

[0035] As to the amount of acrylic ester compound (6) used, it isdesirable that, where the amine compound is a primary amine (i.e., n=1),the acrylic ester compound is used in an amount of 1.0 to 10 moles,preferably 1.6 to 2.4 moles, per mole of the amine compound (5), andwhere the amine compound is a secondary amine (i.e., n=2), the acrylicester compound is used in an amount of 0.5 to 5.0 moles, preferably 0.8to 1.2 moles, per mole of the amine compound (5). The reaction may becarried out in the absence or presence of a solvent.

[0036] Usable solvents include alcohols such as methanol, ethanol,isoproyl alcohol, t-butyl alcohol and ethylene glycol; hydrocarbons suchas hexane, heptane, benzene, toluene and xylene; ethers such as diethylether, dibutyl ether, tetrahydrofuran, 1,4-dioxane and diglyme;chlorine-containing solvents such as methylene chloride, chloroform and1,2-dichloroethylene; aprotic polar solvents such asN,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide andN-methylpyrrolidone; carboxylic acids such as formic acid and aceticacid; esters such as ethyl acetate and butyl acetate; ketones such asacetone and 2-butanone; nitrites such as acetonitrile; amines such aspyridine and triethylamine; and water. Suitable solvents may be selectedfrom the foregoing ones according to the reaction conditions and usedeither alone or in admixture.

[0037] The reaction temperature may range from 0° C. to the refluxtemperature of the solvent and may be determined according to thedesired reaction rate. In order to enhance the reaction rate, there maybe added a catalyst selected from inorganic acids such as hydrochloricacid, sulfuric acid and nitric acid, and salts thereof; and organicacids such as p-toluenesulfonic acid, formic acid, acetic acid, oxalicacid and trifluroacetic acid, and salts thereof. Moreover, in order toprevent the polymerization of the acrylic ester compound, apolymerization inhibitor such as hydroquinone, p-methoxyphenol,benzoquinone or phenylenediamine may be added. As to the reaction time,it is desirable from the viewpoint of yield to bring the reaction tocompletion while tracing it by gas chromatography (GC) or thin-layerchromatography (TLC). However, the reaction time usually ranges fromabout 2 to about 200 hours. The desired ester group-containing tertiaryamine compound (1) can be obtained by concentrating the reaction mixtureunder reduced pressure, either directly or after being subjected to anordinary aqueous work-up. If necessary, the ester group-containingtertiary amine compound thus obtained may further be purified accordingto common techniques such as distillation, chromatography andrecrystallization.

[0038] As a second process, they may be synthesized from 2-aminoethanolor diethanolamine and an acrylic ester compound by two-step reactionscomprising the Michael addition reaction of an amine (first step) andthe acylation or alkylation of a hydroxyl group (second step).

[0039] wherein n is 1 or 2; R¹ and R² each independently represents astraight-chain, branched or cyclic alkyl group of 1 to 20 carbon atomswhich may contain an ether, carbonyl or carbonyloxy group; and Xrepresents a leaving group such as halogen, alkylsulfonyloxy, acyloxy,hydroxyl or aryloxy.

[0040] In the reaction of the first step, it is desirable that, wherethe amine compound is 2-ethanolamine (i.e., n=1), the acrylic estercompound (6) is used in an amount of 1.0 to 10 moles, preferably 1.6 to2.4 moles, per mole of the amine compound (7), and where the aminecompound is diethanolamine (i.e., n=2), the acrylic ester compound isused in an amount of 0.5 to 5.0 moles, preferably 0.8 to 1.2 moles, permole of the amine compound (7). The reaction may be carried out in theabsence or presence of a solvent.

[0041] Usable solvents include alcohols such as methanol, ethanol,isoproyl alcohol, t-butyl alcohol and ethylene glycol; hydrocarbons suchas hexane, heptane, benzene, toluene and xylene; ethers such as diethylether, dibutyl ether, tetrahydrofuran, 1,4-dioxane and diglyme;chlorine-containing solvents such as methylene chloride, chloroform and1,2-dichloroethylene; aprotic polar solvents such asN,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide andN-methylpyrrolidone; carboxylic acids such as formic acid and aceticacid; esters such as ethyl acetate and butyl acetate; ketones such asacetone and 2-butanone; nitrites such as acetonitrile; amines such aspyridine and triethylamine; and water. Suitable solvents may be selectedfrom the foregoing ones according to the reaction conditions and usedeither alone or in admixture. However, it is preferable from theviewpoint of efficiency to use the same solvent as used for the reactionof the next step, because the solvent need not be replaced.

[0042] The reaction temperature may range from 0° C. to the refluxtemperature of the solvent and may be determined according to thedesired reaction rate. In order to enhance the reaction rate, there maybe added a catalyst selected from inorganic acids such as hydrochloricacid, sulfuric acid and nitric acid, and salts thereof; and organicacids such as p-toluenesulfonic acid, formic acid, acetic acid, oxalicacid and trifluroacetic acid, and salts thereof. Moreover, in order toprevent the polymerization of the acrylic ester compound, apolymerization inhibitor such as hydroquinone, p-methoxyphenol,benzoquinone or phenylenediamine may be added. As to the reaction time,it is desirable from the viewpoint of yield to bring the reaction tocompletion while tracing it by gas chromatography (GC) or thin-layerchromatography (TLC). However, the reaction time usually ranges fromabout 2 to about 200 hours. When the reaction is carried out in theabsence of solvent or in the presence of the same solvent as used forthe next step, the reaction of the next step may be continuously carriedout in the same reaction vessel. Alternatively, the aminoalcoholcompound (8) may be obtained as an intermediate product by concentratingthe reaction mixture under reduced pressure, either directly or afterbeing subjected to an ordinary aqueous work-up. If necessary, theaminoalcohol compound (8) thus obtained may further be purifiedaccording to common techniques such as distillation, chromatography andrecrystallization. However, if the crude product has a sufficiently highpurity, it may be directly used for the reaction of the second step.

[0043] In the reaction of the second step, where R¹ is an alkyl group,specific examples of R¹X include, but are not limited to, methyl iodide,butyl bromide, dimethyl sulfate, ethyl iodide, diethyl sulfate,methoxymethyl chloride, (2-methoxyethoxy)methyl chloride, methylchloroacetate and chloroacetone. Where R¹ is an acyl group, specificexamples of R¹X include, but are not limited to, formic acid, aceticformic anhydride, acetic anhydride, acetyl chloride, propionicanhydride, propionyl chloride, butyryl chloride, isobutyryl chloride,valeryl chloride, pivaloyl chloride, methoxyacetyl chloride,acetoxyacetyl chloride, di-t-butyl pyrocarbonate, phenyl acetate,p-nitrophenyl acetate and 2,4,6-trichlorophenyl acetate. As to theamount of R¹X used, it is desirable that, where n=1, R¹X is used in anamount of 0.5 to 5.0 moles, preferably 1.0 to 2.5 moles, per mole of theaminoalcohol compound (8), and where n=2, R¹X is used in an amount of1.0 to 10 moles, preferably 2.0 to 5.0 moles, per mole of theaminoalcohol compound (8). The reaction may be carried out in theabsence or presence of a solvent.

[0044] Usable solvents include hydrocarbons such as hexane, heptane,benzene, toluene and xylene; ethers such as diethyl ether, dibutylether, tetrahydrofuran, 1,4-dioxane and diglyme; chlorine-containingsolvents such as methylene chloride, chloroform and1,2-dichloroethylene; aprotic polar solvents such asN,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide andN-methylpyrrolidone; carboxylic acids such as formic acid and aceticacid; esters such as ethyl acetate and butyl acetate; ketones such asacetone and 2-butanone; nitrites such as acetonitrile; and amines suchas pyridine and triethylamine. Suitable solvents may be selected fromthe foregoing ones according to the reaction conditions and used eitheralone or in admixture.

[0045] A basic compound may be added in order to accelerate thereaction. Specific examples thereof include, but are not limited to,alkali metal or alkaline earth metal salts such as sodium hydroxide,potassium hydroxide, potassium carbonate, sodium carbonate, sodiumbicarbonate, sodium hydride, calcium hydride, potassium t-butoxide andlithium t-butoxide; organometallic compounds such as n-butyl lithium,lithium diisopropylamide, lithium hexamethyldisilazide andbromomagensium diisopropylamide; and organic amines such as pyridine,triethylamine, diisopropylethylamine, N,N-dimethylaniline and4-dimethylaminopyridine. These basic compounds may be used either aloneor in admixture of two or more. They are preferably be used in an amountof 0.8 to 10 moles, more preferably 0.9 to 3.0 moles, per mole of R¹X.

[0046] The reaction temperature may range from −70° C. to the refluxtemperature of the solvent. However, it is preferable to use a reactiontemperature in the range of 0 to 50° C. As to the reaction time, it isdesirable from the viewpoint of yield to bring the reaction tocompletion while tracing it by gas chromatography (GC) or thin-layerchromatography (TLC). However, the reaction time usually ranges fromabout 0.2 to about 20 hours. The desired ester group-containing tertiaryamine compound (1) can be obtained by subjecting the reaction mixture toan ordinary aqueous work-up. If necessary, the compound (1) may furtherbe purified according to common techniques such as distillation,chromatography and recrystallization.

[0047] Finally, as a third process, they may be synthesized bysubjecting another ester group-containing tertiary amine compound of thepresent invention to an ester exchange reaction with an alcohol in thepresence of a catalyst.

[0048] wherein n is 1 or 2; R¹ and R² each independently represents astraight-chain, branched or cyclic alkyl group of 1 to 20 carbon atomswhich may contain an ether, carbonyl or carbonyloxy group; and R⁴represents a lower alkyl group such as methyl, ethyl, propyl or butyl.

[0049] In this reaction, the desired compound (1) is obtained by usingan ester group-containing tertiary amine compound (9) prepared by theabove-described first or second process as a starting material andsubjecting it to an ester exchange reaction with an alcohol (R²OH) inthe presence of a catalyst. This reaction may be carried out in theabsence or presence of a solvent. In order to enhance efficiency andshorten the reaction time, it is preferable to carry out the reactionwhile distilling off the alcohol (R⁴OH) newly formed by the reaction. Itis desirable that the alcohol (R²OH) is used in an amount of 0.5 to 5.0moles, preferably 1.0 to 1.5 moles, per mole of the estergroup-containing tertiary amine compound (9).

[0050] Usable ester exchange catalysts include, but are not limited to,organic amines such as triethylamine, 1,8-diazabicyclo[5.4.0]-7-undeceneand 4-dimethylaminopyridine; inorganic bases such as sodium hydroxide,potassium carbonate and sodium carbonate; metal alkoxides such as sodiummethoxide, potassium t-butoxide, magnesium ethoxide and titanium(IV)methoxide; salts such as iron(III) sulfate and calcium chloride; andinorganic or organic acids such as hydrogen chloride, sulfuric acid andp-toluenesulfonic acid. It is desirable that the ester exchange catalystis used in an amount of 0.001 to 5.0 moles, preferably 0.001 to 0.1moles, per mole of the ester group-containing tertiary amine compound(9).

[0051] Usable solvents include ethers such as tetrahydrofuran,di-n-butyl ether and 1,4-dioxane; hydrocarbons such as n-hexane,n-heptane, benzene, toluene, xylene and cumene; and chlorine-containingsolvents such as chloroform and dichloroethylene. Suitable solvents maybe selected from the foregoing ones and used either alone or inadmixture.

[0052] Although the reaction temperature may vary according to thereaction conditions, it preferably ranges from 50° C. to 200° C. It isespecially preferable to carry out the reaction at a temperature closeto the boiling point of the reaction solvent while distilling off thealcohol (R⁴OH) formed. As to the reaction time, it is desirable from theviewpoint of yield to bring the reaction to completion while tracing itby gas chromatography (GC) or thin-layer chromatography (TLC). However,the reaction time usually ranges from about 1 to about 20 hours. Thedesired ester group-containing tertiary amine compound (1) may beobtained subjecting the reaction mixture to an ordinary aqueous work-up.If necessary, the compound (1) may further be purified according tocommon techniques such as distillation, chromatography andrecrystallization. Alternatively, the desired compound (1) may beobtained by distilling the reaction mixture directly.

[0053] The ester group-containing tertiary amine compounds of thepresent invention which have been prepared in the above-described mannermay be added to chemically amplified resists, either alone or inadmixture of two or more, so that they produce an excellent effect inpreventing a film loss, enhancing the resolution, and extending thefocus margin, regardless of exposure wavelength. In particular, they canbe suitably used in KrF resists, ArF resists, F₂ resists and EB resists.

[0054] The resist materials containing the ester group-containingtertiary amine compounds of the present invention may generally beprepared by compounding a resist base polymer, a photochemical acidgenerator, an organic solvent, and an ester group-containing tertiaryamine compound in accordance with the present invention. If necessary,another type of basic compound, a crosslinker, a dissolution inhibitorand the like may also be added thereto. These resist materials may beprepared in the usual manner.

[0055] The ester group-containing tertiary amine compound of the presentinvention is preferably added in an amount of 0.001 to 2.0 parts byweight, more preferably 0.01 to 1.0 part by weight, per 100 parts byweight of the total base resin. If its amount added is less than 0.001part by weight, its addition may fail to produce an appreciable effect,and if its amount added is greater than 2 parts by weight, the resultingresist material may show an undue reduction in sensitivity.

[0056] The present invention is more specifically explained withreference to the following synthesis examples, reference examples andcomparative reference examples. However, these examples are not to beconstrued to limit the scope of the invention.

SYNTHESIS EXAMPLES

[0057] Among the ester group-containing tertiary amine compounds of thepresent invention, the aforesaid amines 1-81 were synthesized accordingto the formulations described below.

Synthesis Example 1 Synthesis of Amine 1

[0058] 10.5 g of ethyl acrylate was added to 10.5 g of diethanolamine at20-30° C., and the resulting mixture was allowed to stand for 20 hours.After 25.6 g of triethylamine, 100 mg of 4-dimethylaminopyridine, and100 g of THF were added thereto, 22.4 g of acetic anhydride was addedthereto at 20-30° C., followed by stirring for 10 hours. After thereaction was stopped by the addition of water, the reaction mixture wasextracted with ethyl acetate. The organic layer was washed with water,dried over anhydrous sodium sulfate, and concentrated under reducedpressure to obtain 27.5 g (95% yield) of amine 1.

Synthesis Example 2 Synthesis of Amine 2

[0059] Amine 2 was synthesized (in a 96% yield) in the same manner as inSynthesis Example 1, except that propyl acrylate was used in place ofethyl acrylate.

Synthesis Example 3 Synthesis of Amine 3

[0060] Amine 3 was synthesized (in a 94% yield) in the same manner as inSynthesis Example 1, except that isopropyl acrylate was used in place ofethyl acrylate.

Synthesis Example 4 Synthesis of Amine 4

[0061] Amine 4 was synthesized (in a 94% yield) in the same manner as inSynthesis Example 1, except that butyl acrylate was used in place ofethyl acrylate.

Synthesis Example 5 Synthesis of Amine 5

[0062] Amine 5 was synthesized (in a 93% yield) in the same manner as inSynthesis Example 1, except that pentyl acrylate was used in place ofethyl acrylate.

Synthesis Example 6 Synthesis of Amine 6

[0063] Amine 6 was synthesized (in a 95% yield) in the same manner as inSynthesis Example 1, except that hexyl acrylate was used in place ofethyl acrylate.

Synthesis Example 7 Synthesis of Amine 7

[0064] Amine 7 was synthesized (in a 92% yield) in the same manner as inSynthesis Example 1, except that cyclohexyl acrylate was used in placeof ethyl acrylate.

Synthesis Example 8 Synthesis of Amine 8

[0065] Amine 8 was synthesized (in a 90% yield) in the same manner as inSynthesis Example 1, except that decyl acrylate was used in place ofethyl acrylate.

Synthesis Example 9 Synthesis of Amine 9

[0066] Amine 9 was synthesized (in a 88% yield) in the same manner as inSynthesis Example 1, except that pentadecyl acrylate was used in placeof ethyl acrylate.

Synthesis Example 10 Synthesis of Amine 10

[0067] Amine 10 was synthesized (in a 85% yield) in the same manner asin Synthesis Example 1, except that dodecyl acrylate was used in placeof ethyl acrylate.

Synthesis Example 11 (Synthesis of amine 11)

[0068] 11.6 g of 2-hydroxyethyl acrylate was added to 10.5 g ofdiethanolamine at 20-30° C., and the resulting mixture was allowed tostand for 20 hours. After 38.4 g of triethylamine, 150 mg of4-dimethylaminopyridine, and 100 g of THF were added thereto, 33.6 g ofacetic anhydride was added thereto at 20-30° C., followed by stirringfor 10 hours. After the reaction was stopped by the addition of water,the reaction mixture was extracted with ethyl acetate. The organic layerwas washed with water, dried over anhydrous sodium sulfate, andconcentrated under reduced pressure. The resulting residue was purifiedby vacuum distillation to obtain 31.3 g (90% yield) of amine 11 (boilingpoint 164-166° C./27 Pa).

[0069] IR (thin film): ν=2960, 2837, 1740, 1443, 1375, 1236, 1190, 1043cm⁻¹.

[0070]¹H-NMR (300 MHz in CDCl₃): δ=2.02 (6H, s), 2.05 (3H, s), 2.45 (2H,t, J=6.9 Hz), 2.75 (4H, t, J=6.1 Hz), 2.88 (2H, t, J=6.9 Hz), 4.08 (4H,t, J=6.1 Hz), 4.25 (4H, s).

Synthesis Example 12 Synthesis of Amine 12

[0071] Amine 12 was synthesized (in a 86% yield) in the same manner asin Synthesis Example 1, except that 2-methoxyethyl acrylate was used inplace of ethyl acrylate. Boiling point 146-148° C./9.3 Pa.

[0072] IR (thin film): ν=2954, 2893, 2825, 1738, 1456, 1371, 1238, 1198,1130, 1039 cm⁻¹.

[0073]¹H-NMR (300 MHz in CDCl₃): δ=2.02 (6H, s), 2.46 (2H, t, J=7.1 Hz),2.74 (4H, t, J=6.0 Hz), 2.88 (2H, t, J=7.1 Hz), 3.36 (3H, s), 3.56 (2H,m), 4.08 (4H, t, J=6.0 Hz), 4.20 (2H, m).

Synthesis Example 13 Synthesis of Amine 13

[0074] Amine 13 was synthesized (in a 70% yield) in the same manner asin Synthesis Example 1, except that 2-oxotetrahydrofuran-3-yl acrylatewas used in place of ethyl acrylate.

[0075] IR (thin film): ν=2962, 2837, 1792, 1743, 1668, 1456, 1437, 1373,1240, 1196, 1095, 1043 cm⁻¹.

Synthesis Example 14 Synthesis of Amine 14

[0076] Amine 14 was synthesized (in a 60% yield) in the same manner asin Synthesis Example 1, except that (methoxycarbonyl)methyl acrylate wasused in place of ethyl acrylate. Boiling point 154-157° C./17 Pa.

[0077] IR (thin film): ν=2956, 2837, 1740, 1439, 1377, 1236, 1180, 1041cm⁻¹.

[0078]¹H-NMR (300 MHz in CDCl₃): δ=2.02 (6H, s), 2.54 (2H, t, J=7.1 Hz),2.76 (4H, t, J=5.9 Hz), 2.92 (2H, t, J=7.1 Hz), 3.74 (3H, s), 4.09 (4H,t, J=5.9 Hz), 4.59 (2H, s).

Synthesis Example 15 Synthesis of Amine 15

[0079] Amine 15 was synthesized (in a 85% yield) in the same manner asin Synthesis Example 1, except that 2-oxopropyl acrylate was used inplace of ethyl acrylate. Boiling point 165° C./27 Pa.

[0080] IR (thin film): ν=2960, 2837, 1736, 1421, 1373, 1238, 1174, 1041cm⁻¹.

[0081]¹H-NMR (300 MHz in CDCl₃): δ=2.02 (6H, s), 2.13 (3H, s), 2.55 (2H,t, J=7.1 Hz), 2.76 (4H, t, J=5.9 Hz), 2.92 (2H, t, J=7.1 Hz), 4.08 (4H,t, J=5.9 Hz), 4.63 (2H, s).

Synthesis Example 16 Synthesis of Amine 16

[0082] Amine 16 was synthesized (in a 76% yield) in the same manner asin Synthesis Example 1, except that tetrahydrofurfuryl acrylate was usedin place of ethyl acrylate. Boiling point 165° C./20 Pa.

[0083] IR (thin film): ν=2958, 2873, 1740, 1450, 1371, 1238, 1193, 1039cm⁻¹.

[0084]¹H-NMR (300 MHz in CDCl₃): δ=0.56 (1H, m), 1.80-2.10 [10H, mincluding 2.02 (6H, s)], 2.47 (2H, t, J=7.1 Hz), 2.74 (4H, t, J=6.0 Hz),2.88 (2H, t, J=7.1 Hz), 3.70-4.20 [9H, m including 4.06 (4H, t, J=6.0Hz)].

Synthesis Example 17 Synthesis of Amine 17

[0085] Amine 17 was synthesized (in a 88% yield) in the same manner asin Synthesis Example 1, except that 2-(2-methoxyethoxy)ethyl acrylatewas used in place of ethyl acrylate.

Synthesis Example 18 Synthesis of Amine 18

[0086] Amine 18 was synthesized (in a 90% yield) in the same manner asin Synthesis Example 1, except that 2-ethoxyethyl acrylate was used inplace of ethyl acrylate.

Synthesis Example 19 Synthesis of Amine 19

[0087] Amine 19 was synthesized (in a 87% yield) in the same manner asin Synthesis Example 11, except that 4-hydroxybutyl acrylate was used inplace of 2-hydroxyethyl acrylate.

Synthesis Example 20 Synthesis of Amine 20

[0088] Amine 20 was synthesized (in a 80% yield) in the same manner asin Synthesis Example 1, except that methyl acrylate was used in place ofethyl acrylate and acetoxyacetyl chloride was used in place of aceticanhydrate.

Synthesis Example 21 Synthesis of Amine 21

[0089] Amine 21 was synthesized (in a 78% yield) in the same manner asin Synthesis Example 1, except that acetoxyacetyl chloride was used inplace of acetic anhydride.

Synthesis Example 22 Synthesis of Amine 22

[0090] Amine 22 was synthesized (in a 82% yield) in the same manner asin Synthesis Example 1, except that methyl acrylate was used in place ofethyl acrylate, and methoxyacetyl chloride in place of acetic anhydride.

Synthesis Example 23 Synthesis of Amine 23

[0091] Amine 23 was synthesized (in a 80% yield) in the same manner asin Synthesis Example 1, except that methoxyacetyl chloride was used inplace of acetic anhydride.

Synthesis Example 24 Synthesis of Amine 24

[0092] Amine 24 was synthesized (in a 85% yield) in the same manner asin Synthesis Example 1, except that methyl acrylate was used in place ofethyl acrylate, and di-t-butyl pyrocarbonate in place of aceticanhydride.

Synthesis Example 25 Synthesis of Amine 25

[0093] Amine 25 was synthesized (in a 80% yield) in the same manner asin Synthesis Example 1, except that di-t-butyl pyrocarbonate was used inplace of acetic anhydride.

Synthesis Example 26 Synthesis of Amine 26

[0094] Amine 26 was synthesized (in a 82% yield) in the same manner asin Synthesis Example 1, except that methyl acrylate was used in place ofethyl acrylate, and propionyl chloride in place of acetic anhydride.

Synthesis Example 27 Synthesis of Amine 27

[0095] Amine 27 was synthesized (in a 81% yield) in the same manner asin Synthesis Example 1, except that propionyl chloride was used in placeof acetic anhydride.

Synthesis Example 28 Synthesis of Amine 28

[0096] 8.6 g of methyl acrylate was added to 10.5 g of diethanolamine at20-30° C., and the resulting mixture was allowed to stand for 20 hours.Then, 100 g of formic acid was added thereto, followed by stirring at80° C. for 20 hours. After the reaction mixture was diluted with ethylacetate, it was neutralized by the addition of a 5% aqueous solution ofsodium bicarbonate, washed with water, dried over anhydrous sodiumsulfate, and concentrated under reduced pressure to obtain 19.8 g (80%yield) of amine 28.

Synthesis Example 29 Synthesis of Amine 29

[0097] Amine 29 was synthesized (in a 81% yield) in the same manner asin Synthesis Example 28, except that ethyl acrylate was used in place ofmethyl acrylate.

Synthesis Example 30 Synthesis of Amine 30

[0098] Amine 30 was synthesized (in a 40% yield) in the same manner asin Synthesis Example 28, except that 2-hydroxyethyl acrylate was used inplace of methyl acrylate.

[0099] IR (thin film): ν=2956, 2839, 1722, 1456, 1275, 1254, 1173, 1061cm⁻¹.

[0100]¹H-NMR (270 MHz in CDCl₃): δ=2.47 (2H, t, J=7.0 Hz), 2.80 (4H, t,J=5.9 Hz), 2.90 (2H, t, J=7.0 Hz), 4.19 (4H, t, J=5.9 Hz), 4.25-4.40(4H, m), 8.03 (2H, s), 8.06 (1H, s).

Synthesis Example 31 Synthesis of Amine 31

[0101] Amine 31 was synthesized (in a 70% yield) in the same manner asin Synthesis Example 28, except that 4-hydroxybutyl acrylate was used inplace of methyl acrylate.

[0102] IR (thin film): ν=2960, 2839, 1722, 1466, 1363, 1254, 1176, 1065cm⁻¹.

[0103]¹H-NMR (270 MHz in CDCl₃): δ=1.65-1.80 (4H, m), 2.44 (2H, t, J=7.2Hz), 2.80 (4H, t, J=5.8 Hz), 2.89 (2H, t, J=7.2 Hz), 4.05-4.25 (8H, m),8.03 (2H, s), 8.04 (1H, s).

Synthesis Example 32 Synthesis of Amine 32

[0104] Amine 32 was synthesized (in a 81% yield) in the same manner asin Synthesis Example 1, except that methyl acrylate was used in place ofethyl acrylate, and pivaloyl chloride in place of acetic anhydride.

Synthesis Example 33 Synthesis of Amine 33

[0105] Amine 33 was synthesized (in a 80% yield) in the same manner asin Synthesis Example 1, except that pivaloyl chloride was used in placeof acetic anhydride.

Synthesis Example 34 Synthesis of Amine 34

[0106] 13.3 g of bis(2-methoxyethyl)amine was added to a mixture of 10.0g of methyl acrylate and 10.0 g of methanol at 20-30° C., and theresulting mixture was allowed to stand for 200 hours. The reactionmixture was concentrated under reduced pressure and then purified byvacuum distillation to obtain 215 g (98% yield) of amine 34 (boilingpoint 71-75° C./27 Pa).

[0107] IR (thin film): ν=2951, 2927, 2877, 2818, 1740, 1437, 1254, 1198,1119 cm⁻¹.

[0108]¹H-NMR (270 MHz in CDCl₃): δ=2.46 (2H, t, J=7.3 Hz), 2.69 (4H, t,J=6.0 Hz), 2.89 (2H, t, J=7.3 Hz), 3.31 (6H, s), 3.43 (4H, t, J=6.0 Hz),3.64 (3H, s).

Synthesis Example 35 Synthesis of Amine 35

[0109] Amine 35 was synthesized (in a 90% yield) in the same manner asin Synthesis Example 34, except that ethyl acrylate was used in place ofmethyl acrylate (boiling point 74° C./16 Pa).

[0110] IR (thin film): ν=2980, 2929, 2875, 2816, 1734, 1458, 1369, 1302,1252, 1188, 1120, 1049 cm⁻¹.

[0111]¹H-NMR (300 MHz in CDCl₃): δ=1.21 (3H, t, J=7.2 Hz), 2.42 (2H, t,J=6.0 Hz), 2.67 (4H, t, J=6.2 Hz), 2.86 (2H, t, J=6.0 Hz), 3.29 (6H, s),3.41 (4H, t, J=6.2 Hz), 4.08 (2H, q, J=7.2 Hz).

Synthesis Example 36 Synthesis of Amine 36

[0112] Amine 36 was synthesized (in a 89% yield) in the same manner asin Synthesis Example 34, except that propyl acrylate was used in placeof methyl acrylate.

Synthesis Example 37 Synthesis of Amine 37

[0113] Amine 37 was synthesized (in a 90% yield) in the same manner asin Synthesis Example 34, except that butyl acrylate was used in place ofmethyl acrylate.

Synthesis Example 38 Synthesis of Amine 38

[0114] Amine 38 was synthesized (in a 88% yield) in the same manner asin Synthesis Example 34, except that pentyl acrylate was used in placeof methyl acrylate.

Synthesis Example 39 Synthesis of Amine 39

[0115] Amine 39 was synthesized (in a 87% yield) in the same manner asin Synthesis Example 34, except that hexyl acrylate was used in place ofmethyl acrylate. Boiling point 121° C./16 Pa.

[0116] IR (thin film): ν=2956, 2929, 2873, 2816, 1736, 1460, 1248, 1184,1120, 1068, 1012 cm⁻¹.

[0117]¹H-NMR (300 MHz in CDCl₃): δ=0.87 (3H, m), 1.20-1.40 (6H, m), 1.59(2H, m), 2.45 (2H, t, J=7.2 Hz), 2.70 (4H, t, J=5.9 Hz), 2.89 (2H, t,J=7.2 Hz), 3.31 (6H, s), 3.44 (4H, t, J=5.9 Hz), 4.04 (2H, t, J=6.8 Hz).

Synthesis Example 40 Synthesis of Amine 40

[0118] Amine 40 was synthesized (in a 85% yield) in the same manner asin Synthesis Example 34, except that cyclohexyl acrylate was used inplace of methyl acrylate.

Synthesis Example 41 Synthesis of Amine 41

[0119] Amine 41 was synthesized (in a 89% yield) in the same manner asin Synthesis Example 34, except that 2-ethylhexyl acrylate was used inplace of methyl acrylate.

Synthesis Example 42 Synthesis of Amine 42

[0120] Amine 42 was synthesized (in a 90% yield) in the same manner asin Synthesis Example 34, except that 2-methoxyethyl acrylate was used inplace of methyl acrylate.

Synthesis Example 43 Synthesis of Amine 43

[0121] Amine 43 was synthesized (in a 89% yield) in the same manner asin Synthesis Example 34, except that 2-ethoxyethyl acrylate was used inplace of methyl acrylate.

Synthesis Example 44 Synthesis of Amine 44

[0122] Amine 44 was synthesized (in a 88% yield) in the same manner asin Synthesis Example 34, except that 2-propoxyethyl acrylate was used inplace of methyl acrylate.

Synthesis Example 45 Synthesis of Amine 45

[0123] Amine 45 was synthesized (in a 87% yield) in the same manner asin Synthesis Example 34, except that 2-isopropoxyethyl acrylate was usedin place of methyl acrylate.

Synthesis Example 46 Synthesis of Amine 46

[0124] Amine 46 was synthesized (in a 89% yield) in the same manner asin Synthesis Example 34, except that 2-butoxyethyl acrylate was used inplace of methyl acrylate.

Synthesis Example 47 Synthesis of Amine 47

[0125] Amine 47 was synthesized (in a 91% yield) in the same manner asin Synthesis Example 34, except that 2-(2-methoxyethoxy)ethyl acrylatewas used in place of methyl acrylate.

Synthesis Example 48 Synthesis of Amine 48

[0126] Amine 48 was synthesized (in a 70% yield) in the same manner asin Synthesis Example 34, except that tetrahydrofurfuryl acrylate wasused in place of methyl acrylate (boiling point 130° C./14 Pa).

[0127] IR (thin film): ν=2976, 2947, 2929, 2875, 1736, 1458, 1389, 1363,1250, 1184, 1119, 1078, 1024 cm⁻¹.

[0128]¹H-NMR (300 MHz in CDCl₃): δ=1.56 (1H, m), 1.75-2.05 (3H, m), 2.50(2H, t, J=7.2 Hz), 2.69 (4H, t, J=6.0 Hz), 3.70-4.20 (5H, m).

Synthesis Example 49 Synthesis of Amine 49

[0129] Amine 49 was synthesized (in a 88% yield) in the same manner asin Synthesis Example 34, except that 2-oxopropyl acrylate was used inplace of methyl acrylate.

Synthesis Example 50 Synthesis of Amine 50

[0130] Amine 50 was synthesized (in a 90% yield) in the same manner asin Synthesis Example 34, except that 2-acetoxyethyl acrylate was used inplace of methyl acrylate.

Synthesis Example 51 Synthesis of Amine 51

[0131] Amine 51 was synthesized (in a 84% yield) in the same manner asin Synthesis Example 34, except that 4-acetoxybutyl acrylate was used inplace of methyl acrylate. Boiling point 137° C./19 Pa.

[0132] IR (thin film): ν=2954, 2929, 2875, 2815, 1738, 1458, 1389, 1365,1240, 1184, 1119, 1047 cm⁻¹.

[0133]¹H-NMR (300 MHz in CDCl₃): δ=1.68 (4H, m), 2.03 (3H, s), 2.46 (2H,br.t, J=7.3 Hz), 2.70 (4H, br.t, J=5.9 Hz), 2.89 (2H, br.t, J=7.3 Hz),3.31 (6H, s), 2.43 (4H, br.t, J=5.9 Hz), 4.07 (4H, m).

Synthesis Example 52 Synthesis of Amine 52

[0134] Amine 52 was synthesized (in a 80% yield) in the same manner asin Synthesis Example 34, except that 2-(acetoxyacetoxy)ethyl acrylatewas used in place of methyl acrylate.

Synthesis Example 53 Synthesis of Amine 53

[0135] Amine 53 was synthesized (in a 83% yield) in the same manner asin Synthesis Example 34, except that 2-(t-butoxycarbonyloxy)ethylacrylate was used in place of methyl acrylate.

Synthesis Example 54 Synthesis of Amine 54

[0136] Amine 54 was synthesized (in a 79% yield) in the same manner asin Synthesis Example 34, except that 2-(methoxycarbonylmethoxy)ethylacrylate was used in place of methyl acrylate.

Synthesis Example 55 Synthesis of Amine 55

[0137] 17.5 g of methyl acrylate was added to 6.11 g of 2-aminoethanolat 20-30° C., and the resulting mixture was allowed to stand for 20hours. Then, 12.1 g of triethylamine, 50 mg of 4-dimethylaminopyridine,and 50 g of THF were added thereto. Thereafter, 11.2 g of aceticanhydride was added thereto at 20-30° C., followed by stirring for 5hours. After the reaction was stopped by the addition of water, thereaction mixture was extracted with ethyl acetate, the organic layer waswashed with water, dried over anhydrous sodium sulfate, and concentratedunder reduced pressure. The resulting residue was purified by vacuumdistillation to obtain 26.2 g (95% yield) of amine 55 (boiling point120° C./15 Pa).

[0138] IR (thin film): ν=2954, 2839, 1740, 1439, 1373, 1238, 1200, 1176,1039 cm⁻¹.

[0139]¹H-NMR (300 MHz in CDCl₃): δ=2.01 (3H, s), 2.41 (4H, t, J=6.9 Hz),2.67 (2H, t, J=6.0 Hz), 2.79 (4H, t, J=6.9 Hz), 3.63 (6H, s), 4.06 (2H,t, J=6.0 Hz).

Synthesis Example 56 Synthesis of Amine 56

[0140] Amine 56 was synthesized (in a 93% yield) in the same manner asin Synthesis Example 55, except that ethyl acrylate was used in place ofmethyl acrylate.

Synthesis Example 57 Synthesis of Amine 57

[0141] Amine 57 was synthesized (in a 91% yield) in the same manner asin Synthesis Example 55, except that propyl acrylate was used in placeof methyl acrylate.

Synthesis Example 58 Synthesis of Amine 58

[0142] Amine 58 was synthesized (in a 90% yield) in the same manner asin Synthesis Example 55, except that 2-methoxyethyl acrylate was used inplace of methyl acrylate.

Synthesis Example 59 Synthesis of Amine 59

[0143] Amine 59 was synthesized (in a 88% yield) in the same manner asin Synthesis Example 55, except that 2-acetoxyethyl acrylate was used inplace of methyl acrylate.

Synthesis Example 60 Synthesis of Amine 60

[0144] Amine 60 was synthesized (in a 83% yield) in the same manner asin Synthesis Example 55, except that acetoxyacetyl chloride was used inplace of acetic anhydride.

Synthesis Example 61 Synthesis of Amine 61

[0145] Amine 61 was synthesized (in a 82% yield) in the same manner asin Synthesis Example 55, except that ethyl acrylate was used in place ofmethyl acrylate, and acetoxyacetyl chloride in place of aceticanhydride.

Synthesis Example 62 Synthesis of Amine 62

[0146] Amine 62 was synthesized (in a 85% yield) in the same manner asin Synthesis Example 55, except that methoxyacetyl chloride was used inplace of acetic anhydride.

Synthesis Example 63 Synthesis of Amine 63

[0147] Amine 63 was synthesized (in a 84% yield) in the same manner asin Synthesis Example 55, except that ethyl acrylate was used in place ofmethyl acrylate, and methoxyacetyl hloride in place of acetic anhydride.

Synthesis Example 64 Synthesis of Amine 64

[0148] Amine 64 was synthesized (in a 87% yield) in the same manner asin Synthesis Example 55, except that di-t-butyl pyrocarbonate was usedin place of acetic anhydride.

Synthesis Example 65 Synthesis of Amine 65

[0149] Amine 65 was synthesized (in a 86% yield) in the same manner asin Synthesis Example 55, except that ethyl acrylate was used in place ofmethyl acrylate, and di-t-butyl pyrocarbonate in place of aceticanhydride.

Synthesis Example 66 Synthesis of Amine 66

[0150] Amine 66 was synthesized (in a 85% yield) in the same manner asin Synthesis Example 55, except that propionyl chloride was used inplace of acetic anhydride.

Synthesis Example 67 Synthesis of Amine 67

[0151] Amine 67 was synthesized (in a 83% yield) in the same manner asin Synthesis Example 55, except that ethyl acrylate was used in place ofmethyl acrylate, and propionyl chloride in place of acetic anhydride.

Synthesis Example 68 Synthesis of Amine 68

[0152] 17.5 g of methyl acrylate was added to 6.11 g of 2-aminoethanolat 20-30° C., and the resulting mixture was allowed to stand for 20hours. Then, 100 g of formic acid was added thereto, followed bystirring at 80° C. for 20 hours. After the reaction mixture was dilutedwith ethyl acetate, it was neutralized with a 5% aqueous solution ofsodium bicarbonate, washed with water, dried over anhydrous sodiumsulfate, and concentrated under reduced pressure. The resulting residuewas purified by vacuum distillation to obtain amine 68 (in a 75% yield).

Synthesis Example 69 Synthesis of Amine 69

[0153] Amine 69 was synthesized (in a 76% yield) in the same manner asin Synthesis Example 68, except that ethyl acrylate was used in place ofmethyl acrylate.

Synthesis Example 70 Synthesis of Amine 70

[0154] Amine 70 was synthesized (in a 83% yield) in the same manner asin Synthesis Example 55, except that pivaloyl chloride was used in placeof acetic anhydride.

Synthesis Example 71 Synthesis of Amine 71

[0155] Amine 71 was synthesized (in a 82% yield) in the same manner asin Synthesis Example 55, except that ethyl acrylate was used in place ofmethyl acrylate, and pivaloyl chloride in place of acetic anhydride.

Synthesis Example 72 Synthesis of Amine 72

[0156] 7.5 g of 2-methoxyethylamine was added to a mixture of 20.0 g ofmethyl acrylate and 10.0 g of methanol at 20-30° C., and the resultingmixture was allowed to stand for 200 hours. The reaction mixture wasconcentrated under reduced pressure and then purified by vacuumdistillation to obtain 23.5 g (95% yield) of amine 72 (boiling point81-85° C./27 Pa).

[0157] IR (thin film): ν=2953, 2839, 1740, 1437, 1255, 1200, 1176, 1119cm⁻¹.

[0158]¹H-NMR (270 MHz in CDCl₃): δ=2.44 (4H, t, J=7.2 Hz), 2.63 (2H, t,J=6.1 Hz), 2.81 (4H, t, J=7.2 Hz), 3.31 (3H, s), 3.41 (2H, t, J=6.1 Hz),3.64 (6H, s).

Synthesis Example 73 Synthesis of Amine 73

[0159] Amine 73 was synthesized (in a 93% yield) in the same manner asin Synthesis Example 72, except that ethyl acrylate was used in place ofmethyl acrylate (boiling point 120° C./80 Pa).

[0160] IR (thin film): ν=2981, 2933, 2875, 2825, 1734, 1464, 1371, 1302,1254, 1182, 1119, 1045 cm⁻¹.

[0161]¹H-NMR (300 MHz in CDCl₃): δ=1.23 (6H, t, J=7.1 Hz), 2.42 (4H, t,J=7.2 Hz), 2.63 (2H, t, J=6.2 Hz), 2.81 (4H, t, J=7.2 Hz), 3.31 (3H, s),3.41 (2H, t, J=6.2 Hz), 4.09 (4H, q, J=7.1 Hz).

Synthesis Example 74 Synthesis of Amine 74

[0162] Amine 74 was synthesized (in a 91% yield) in the same manner asin Synthesis Example 72, except that propyl acrylate was used in placeof methyl acrylate.

Synthesis Example 75 Synthesis of Amine 75

[0163] Amine 75 was synthesized (in a 91% yield) in the same manner asin Synthesis Example 72, except that 2-methoxyethyl acrylate was used inplace of methyl acrylate.

Synthesis Example 76 Synthesis of Amine 76

[0164] Amine 76 was synthesized (in a 85% yield) in the same manner asin Synthesis Example 72, except that 2-acetoxyethyl acrylate was used inplace of methyl acrylate.

Synthesis Example 77 Synthesis of Amine 77

[0165] 8.6 g of methyl acrylate was added to 7.5 g of2-methoxyethylamine at 20-30° C., and the resulting mixture was stirredfor 10 hours. Then, 15.0 g of ethyl acrylate was added thereto, followedby stirring for 200 hours. The react ion mixture was concentrated underreduced pressure to obtain amine 77 (in a 97% yield).

Synthesis Example 78 Synthesis of Amine 78

[0166] Amine 78 was synthesized (in a 90% yield) in the same manner asin Synthesis Example 55, except that 2-(2-aminoethoxy)ethanol was usedin place of 2-aminoethanol.

Synthesis Example 79 Synthesis of Amine 79

[0167] Amine 79 was synthesized (in a 74% yield) in the same manner asin Synthesis Example 68, except that 2-(2-aminoethoxy)ethanol was usedin place of 2-aminoethanol.

Synthesis Example 80 Synthesis of Amine 80

[0168] A mixture composed of 21.9 g of amine 34, 10.4 g of(1,3-dioxolan-4-yl)methanol, 100 mg of sodium methoxide, and 60 g ofbenzene was heated under reflux for 5 hours, during which time themethanol resulting from the reaction was distilled off. The reactionmixture was concentrated under reduced pressure and then purified byvacuum distillation to obtain amine 80 (in a 90% yield).

Synthesis Example 81 Synthesis of Amine 81

[0169] Amine 81 was synthesized (in a 81% yield) in the same manner asin Synthesis Example 80, except that tetrahydropyran-4-ol was used inplace of (1,3-dioxolan-4-yl)methanol.

REFERENCE EXAMPLES AND COMPARATIVE REFERENCE EXAMPLES

[0170] Ester group-containing tertiary amine compounds in accordancewith the present invention were added to photoresists, and the effect oftheir addition was evaluated according to the method described below.With respect to the polymers used, their structure, weight-averagemolecular weight (Mw), and ratio of Mw to number-average molecularweight (Mn) will be given later. Average molecular weights weredetermined on a polystyrene basis by gel permeation chromatography(GPC).

[0171] A resist solution was prepared by dissolving a polymer, an acidgenerator, a base, a dissolution inhibitor and a crosslinker in asolvent mixture composed of propylene glycol monomethyl ether acetate(PGMEA) and ethyl lactate (EL) in a weight ratio of 70:30, and filteringthis solution through a Teflon filter having a pore diameter of 0.1 μm.

[0172] Then, a substrate was prepared by forming a 55 nm thick film ofDUV-30 (manufactured by Nissan Chemical Industries Ltd.) on a siliconwafer so that its reflectivity to KrF light (248 nm) was reduced to 1%or less. The above resist solution was spin-coated onto the substrateand baked on a hot plate at 100° C. for 90 seconds to form a resist filmhaving a thickness of 550 nm.

[0173] Using an excimer laser stepper (NSR-S202A, manufactured by NikonCorp.; NA=0.5; σ=0.75; ⅔ annular illumination), the resist film wasexposed to light with variation in exposure and with a shift of thefocus. Immediately after exposure, the resist film was baked at 110° C.for 90 seconds and developed by soaking it in a 2.38% aqueous solutionof tetramethylammonium hydroxide for 60 seconds.

[0174] The resist patterns thus obtained were evaluated in the followingmanner. The results are shown in the reference example tables (Tables 1and 2) and the comparative reference example table (Table 3).

[0175] (Evaluation Method)

[0176] The exposure which can resolve 0.16 μm lines and spaces 1:1 wasdefined as the optimum exposure (Eop) and used for the evaluation of theresist sensitivity. Then, the focus margin was determined at thisexposure. The focus margin was defined on the basis of the fact that thepatterns showed no film loss and the pattern size was 0.16 μm±10% orless.

[0177] It has been confirmed by the results thus obtained that thephotoresists prepared by adding the ester group-containing tertiaryamine compounds of the present invention have a much wider focus margin,as compared with conventional photoresists. TABLE 1 Dissolution Acidinhibitor or generator Base crosslinker Focus Reference Polymer (partsby (parts by (parts by Sensitivity margin Example (parts by weight)weight) weight) weight) (mJ/cm²) (μm) 1 1 PAG2 Amine2 — 30 0.9 (100) (2)(0.1) 2 1 PAG2 Amine10 — 35 0.8 (100) (2) (0.1) 3 1 PAG2 Amine17 — 311.0 (100) (2) (0.1) 4 1 PAG2 Amine18 — 30 1.0 (100) (2) (0.12) 5 1 PAG2Amine19 — 33 1.0 (100) (2) (0.12) 6 1 PAG2 Amine35 — 28 1.0 (100) (2)(0.12) 7 1 PAG2 Amine39 — 32 1.0 (100) (2) (0.1) 8 1 PAG2 Amine57 — 391.0 (100) (2) (0.12) 9 1 PAG2 Amine81 — 38 1.0 (100) (2) (0.16) 10 1PAG2 Amine73 — 40 1.0 (100) (2) (0.16) 11 2 PAG2 Amine73 — 35 0.6 (100)(2) (0.1) 12 3 PAG2 Amine73 — 31 1.1 (100) (2) (0.1) 13 4 PAG2 Amine73crosslinker 38 0.8 (100) (2) (0.1) (15) 14 5 PAG1 Amine73 — 33 0.8 (100)(2) (0.1) 15 6 PAG1 Amine73 — 46 1.0 (100) (2) (0.1) 16 7 PAG1 Amine73 —48 1.0 (100) (2) (0.1) 17 8 PAG1 Amine73 — 42 1.0 (100) (2) (0.1) 18 9PAG1 Amine73 — 43 0.9 (100) (2) (0.1)

[0178] TABLE 2 Dissolution Acid inhibitor Polymer generator Base orcrosslinker Focus Reference (parts by (parts (parts by (parts bySensitivity margin Example weight) by weeight) weight) weight) (mJ/cm²)(μm) 19 10 PAG1 Amine73 — 40 1.1 (100) (2) (0.1) 20 11 PAG1 Amine73 — 410.8 (100) (2) (0.1) 21 12 PAG1 Amine73 — 39 0.9 (100) (2) (0.1) 22 13PAG1 Amine73 — 44 0.9 (100) (2) (0.1) 23 14 PAG1 Amine73 — 43 0.8 (100)(2) (0.1) 24  2 PAG2 Amine73 DRI 31 0.8 (100) (2) (0.1) (20)

[0179] TABLE 3 Dissolution Acid inhibitor or Compartative Polymergenerator Base crosslinker Focus Reference (parts by (parts by (parts by(parts by Sensitivity margin Example weight) weight) weight) weight)(mJ/cm²) (μm) 1 1 PAG2 — — 5 0 (100) (2) 2 1 PAG2 Proton — 30 0.4 (100)(2) sponge (0.2) 3 1 PAG2 DBN — 25 0.4 (100) (2) (0.1) 4 1 PAG2trietanol- — 28 0.6 (100) (2) amine (0.1) 5 2 PAG2 DBN — 35 0.2 (100)(2) (0.1) 6 3 PAG2 DBN — 31 0.5 (100) (2) (0.1) 7 4 PAG2 DBN crosslinker38 0.3 (100) (2) (0.1) (15) 8 5 PAG1 DBN — 33 0.3 (100) (2) (0.1) 9 6PAG1 DBN — 46 0.6 (100) (2) (0.1) 10 7 PAG1 DBN — 48 0.6 (100) (2) (0.1)11 8 PAG1 DBN — 42 0.3 (100) (2) (0.1) 12 9 PAG1 DBN — 35 0.4 (100) (2)(0.1) 13 10  PAG1 DBN — 37 0.3 (100) (2) (0.1) 14 11  PAG1 DBN — 40 0.5(100) (2) (0.1) 15 12  PAG1 DBN — 39 0.4 (100) (2) (0.1) 16 13  PAG1 DBN— 36 0.3 (100) (2) (0.1) 17 14  PAG1 DBN — 37 0.3 (100) (2) (0.1) 18 2PAG2 DBN DRI 31 0.4 (100) (2) (0.1) (20)

[0180]

1. An ester group-containing tertiary amine compound represented by thefollowing general formula (1). (R¹OCH₂CH₂)_(n)N(CH₂CH₂CO₂R²)_(3-n)  (1)wherein n is 1 or 2; and R¹ and R² each independently represents astraight-chain, branched or cyclic alkyl group of 1 to 20 carbon atomswhich may contain an ether, carbonyl or carbonyloxy group.
 2. An estergroup-containing tertiary amine compound as claimed in claim 1 wherein,in the above general formula (1), R¹ has 1 to 10 carbon atoms and R² has2 to 10 carbon atoms.
 3. An ester group-containing tertiary aminecompound as claimed in claim 1 wherein, in the above general formula(1), R¹ is a formyl or acetyl group and R² has 2 to 10 carbon atoms. 4.An ester group-containing tertiary amine compound as claimed in claim 2wherein, in the above general formula (1), R¹ is a formyl or acetylgroup and R² has 2 to 10 carbon atoms.
 5. An ester group-containingtertiary amine compound as claimed in claim 1 wherein, in the abovegeneral formula (1), R¹ is a methyl group and R² has 2 to 10 carbonatoms.
 6. An ester group-containing tertiary amine compound as claimedin claim 2 wherein, in the above general formula (1), R¹ is a methylgroup and R² has 2 to 10 carbon atoms.
 7. A process for the preparationof an ester group-containing tertiary amine compound represented by thefollowing general formula (1), the process comprising the step ofsubjecting a primary or secondary amine compound represented by thefollowing general formula (5) to Michael addition to an acrylic estercompound represented by the following general formula (6).(R¹OCH₂CH₂)_(n)NH_(3-n)  (5)

(R¹OCH₂CH₂)_(n)N(CH₂CH₂CO₂R²)_(3-n)  (1) wherein n is 1 or 2; and R¹ andR² each independently represents a straight-chain, branched or cyclicalkyl group of 1 to 20 carbon atoms which may contain an ether, carbonylor carbonyloxy group.
 8. A process for the preparation of an estergroup-containing tertiary amine compound represented by the followinggeneral formula (1), the process comprising the steps of subjectingmonoethanolamine or diethanolamine represented by the following generalformula (7) to Michael addition to an acrylic ester compound representedby the following general formula (6) so as to form an estergroup-containing ethanolamine compound represented by the followinggeneral formula (8), and introducing the following R¹ group thereinto.(HOCH₂CH₂)_(n)NH_(3-n)  (7)

(HOCH₂CH₂)_(n)N(CH₂CH₂CO₂R²)_(3-n)  (8)(R¹OCH₂CH₂)_(n)N(CH₂CH₂CO₂R²)_(3-n)  (1) wherein n is 1 or 2; and R¹ andR² each independently represents a straight-chain, branched or cyclicalkyl group of 1 to 20 carbon atoms which may contain an ether, carbonylor carbonyloxy group.
 9. A process for the preparation of an estergroup-containing tertiary amine compound represented by the followinggeneral formula (1), the process comprising the step of effecting theester exchange reaction of an ester group-containing tertiary aminerepresented by the following general formula (9), with an alcoholrepresented by the general formula R²OH (wherein R² represents astraight-chain, branched or cyclic alkyl group of 1 to 20 carbon atomswhich may contain an ether, carbonyl or carbonyloxy group).(R¹OCH₂CH₂)_(n)N(CH₂CH₂CO₂R⁴)_(3-n)  (9)(R¹OCH₂CH₂)_(n)N(CH₂CH₂CO₂R²)_(3-n)  (1) wherein n is 1 or 2; and R¹ andR² each independently represents a straight-chain, branched or cyclicalkyl group of 1 to 20 carbon atoms which may contain an ether, carbonylor carbonyloxy group.